Universal roller unit for a treadmill

ABSTRACT

A universal roller unit for a treadmill having a supporting frame and a platform. The supporting frame includes a front and a rear bar at the bottom thereof. A roller is pivotally connected to both ends of the front bar. A universal roller unit is attached to the middle part of the rear bar. When the treadmill is in a flat operational position, the universal roller unit may be attached to the side wall of the rear bar; when the treadmill is in a folded storage position, the universal roller unit may be pushed outwards to allow the universal roller to contact with the ground so that the universal roller and the rollers take the responsibility of supporting the whole weight of the treadmill and move the treadmill stably and freely in any direction.

BACKGROUND OF THE INVENTION

1. Fields of the Invention

The invention relates to a roller unit for a treadmill, and more particularly, to a roller unit having improved convenience in use.

2. Description of the Prior Art

Rollers fitted at the bottom of treadmills are used to facilitate a smooth movement of the treadmill, thereby achieving the laborsaving effect. A typical product is disclosed in U.S. Pat. No. 5,672,140 that describes roller sets are axially and pivotably arranged at one end of the ground-touching cross bars at both sides of the bottom of the treadmill while the roller sets in storage position are not in contact with the ground. In use, the roller sets are used as a pivoting point to incline the main body of the treadmill so as to facilitate the movement of the treadmill. Although this prior art can exactly reach the expected effect, it's difficult for weak people to incline the heavy treadmill during its whole movement. Even, this could lead to an unnecessary accident.

Besides, the design of four rollers directly and permanently in contact with the ground can be seen in U.S. Pat. No. 5,372,559. However, this kind of structure will cause an unexpected sliding or shaking when the treadmill is operated. As a result, the safety of the user is seriously affected and it gradually becomes extinct on the market.

In order to effectively resolve the above-mentioned problems, a support member is provided at proper position of the roller set so as to increase the frictional resistance with the ground. This structure is disclosed in U.S. Pat. No. 6,090,016. However, a swinging see-saw effect will be created when the treadmill is moved on an uneven surface, thereby leading to inconvenience and difficulty of the horizontal adjustment.

SUMMARY OF THE INVENTION

In consideration of the above-mentioned, the inventor of the present invention thinks that the displacement of the treadmill is not a regular action. In operational position, it's not required to use the roller sets. In storage position, it's not necessarily required to shift the treadmill. As a result, partial roller sets can be stored and kept away from the ground so as to eliminate the unexpected sliding shift. In brief, all rollers are pulled out only when it's really required to displace the treadmill. It's therefore an object of the invention to provide a room for accommodating a universal roller unit at the side wall of a rear bar of the supporting frame, thereby eliminating potential drawbacks of the conventional treadmill in respect of the design and the application.

BRIEF DESCRIPTION OF THE DRAWINGS

The accomplishment of this and other objects of the invention will become apparent from the following description and its accompanying drawings of which:

FIG. 1 is a perspective view of a treadmill with a universal roller unit in accordance with the invention;

FIG. 2 is a side view of the treadmill of FIG. 1 in a flat operational position;

FIG. 3 is a perspective exploded view of the universal roller unit and the supporting frame in accordance with the invention;

FIG. 4 is a side view of the treadmill of FIG. 2 in a folded position, showing that the front bar of the supporting frame tilts to the side;

FIG. 5 is a side view of the treadmill of FIG. 2 in a folded position, showing that the universal roller is swiveled outwardly in an operational position; and

FIG. 6 is a side view of the treadmill of FIG. 2 in a folded position, showing that the universal roller is in contact with the ground.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIGS. 1, 2 and 3, a treadmill 10 in accordance with the invention includes:

a supporting frame 20 positioned at the front end of a platform 30, a handrail 21 and an electric console 22 being disposed above the supporting frame 20, a front and a rear bar 23, 24 being attached to the supporting frame 20, a roller 25 being provided at both ends of the front bar 23, respectively, a universal roller unit 40 being provided in the middle of the rear bar 24;

a platform 30 in rectangular shape having a continuous belt 32 driven by a motor transmission unit (not shown) and movable around the platform 30, a support bar 34 being fitted to the bottom of the rear end of the platform 30. By assembling the above-mentioned components, the platform 30 on the supporting frame 20 can be folded in an upright storage position or in a flat operational position.

The universal roller unit 40 includes:

an angle iron 41 attached to the side wall of the rear bar 24 in cooperation with a fastening element 42 and a compression pin 43;

a compression pin 43 passing through a borehole 26 in the rear bar 24, the compression pin 43 having different outer diameters, the borehole 26 also having different inner diameters at both ends thereof so that an unexpected detachment of the compression pin 43 from the borehole 26 can be avoided; and

a universal roller 44 in cooperation with a pivot 45 and two spring elements 46 pivotally connected to a positioning ear 27 under the borehole 26 of the rear bar 24.

In the ordinary state, the universal roller 44 is upwardly swiveled to contact with a corresponding end of the compression pin 43.

When the platform 30 is in flat operational position, the universal roller unit 40 is attached to the side wall of the rear bar 24 without contact to the ground. When the platform 30 is in folded position, as shown in FIGS. 4 through 6, the operator may push the angle iron 41 together with the compression pin 43 in the direction of the universal roller 44. In this way, the universal roller 44 is swiveled to the ground. Meanwhile, the operator put the treadmill 10 down to allow the universal roller 44 to contact with the ground. At that time, the universal roller 44 and the rollers 25 at both sides of the front bar 23 take the responsibility of supporting the whole weight of the treadmill 10 and move the treadmill 10 stably and freely in any direction.

To bring the universal roller unit 40 back to the storage position, the treadmill 10 is required to tilt to the side while the angle iron 41 is pulled back in the reverse direction.

Many changes and modifications in the above-described embodiment of the invention can, of course, be carried out without departing from the scope thereof. Accordingly, to promote the progress in science and the useful arts, the invention is disclosed and is intended to be limited only by the scope of the appended claims. 

1. A universal roller unit for a treadmill having a supporting frame and a platform, the platform being hinged on the supporting frame in a folded storage and a flat operational position, the supporting frame having a front and a rear bar at the bottom thereof, a roller being pivotally connected to both ends of the front bar, a universal roller unit being attached to the middle part of the rear bar, whereby, when the treadmill is in a flat operational position, the universal roller unit may be attached to the side wall of the rear bar; when the treadmill is in a folded storage position, the universal roller unit may be pushed outwards to allow the universal roller to contact with the ground so that the universal roller and the rollers take the responsibility of supporting the whole weight of the treadmill and move the treadmill stably and freely in any direction.
 2. The universal roller unit for a treadmill as claimed in claim 1 wherein the universal roller unit comprising: a) an angle iron attached to the side wall of the rear bar in cooperation with a fastening element and a compression pin; b) a compression pin passing through a borehole in the rear bar, the compression pin having different outer diameters, the borehole also having different inner diameters at both ends thereof so that an unexpected detachment of the compression pin from the borehole can be avoided; and c) a universal roller in cooperation with a pivot and two spring elements pivotally connected to a positioning ear under the borehole of the rear bar, whereby, in the ordinary state, the universal roller is upwardly swiveled to contact with a corresponding end of the compression pin. 